[PATCH v2 0/7] iio: core: Introduce cleanup.h support for mode locks

[Kurt Borja <kuurtb@gmail.com>]

Hi,

In a recent driver review discussion [1], Andy Shevchenko suggested we
add cleanup.h support for the lock API:

	iio_device_claim_{direct,buffer_mode}().

Which would allow some nice code simplification in many places. Some
examples are given as patches, but the last two are the biggest
differences.

In this version I dropped the RFC tag, as the general feeling is to go
through with this after some modifications. Main one is the addition of
IIO_DEV_ACQUIRE_{BUFFER,CLAIM}_MODE() wrappers to avoid drivers using
the guard classes directly. I also added comments on the forbidden ways
to use this API but I definitely still take suggestions on this.

For now I dropped iio_device_claim_buffer_mode() rename, as this point
is still being discussed. My suggestion based on the RFC discussion is
to do it, but in a separate patch (using coccinelle) and while we're at
it rename the whole API like this:

	iio_dev_mode_lock()
	iio_dev_mode_direct_trylock()
	iio_dev_mode_buffer_trylock()
	iio_dev_mode_unlock()

Let me know what you think and thanks for taking a look! The RFC
discussion was a bit long so apologies if I overlooked some comment.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
v2:
  - Add __iio_dev_mode_lock() (formerly iio_device_claim()) in the first
    patch.
  - Added comments to make sure __iio_dev_mode_lock() is not used by
    drivers to protect internal state, or in general.
  - Add patch which re-implements iio_device_claim_direct() using
    __iio_dev_mode_lock().
  - Match iio_device_claim_buffer_mode() semantics by reimplementing it
    in the same way as iio_device_claim_direct().
  - Guard classes now are prefixed with __priv__ to make sure drivers
    don't use them directly.
  - Add IIO_DEV_ACQUIRE_{BUFFER,DIRECT}_MODE() documented wrappers
  - Avoid any function renames (for now).
  - Rename dummy variable `claim` instead of `busy` on vcnl4000 patch.
  - Avoid scoped guard in max30102.
  - Keep using iio_trigger_validate_own_device() insted of
    iio_trigger_using_own() in opt4060.
  - Link to v1: https://lore.kernel.org/r/20251203-lock-impr-v1-0-b4a1fd639423@gmail.com

---
Kurt Borja (7):
      iio: core: Add and export __iio_dev_mode_lock()
      iio: core: Refactor iio_device_claim_direct() implementation
      iio: core: Match iio_device_claim_*() semantics and implementation
      iio: core: Add cleanup.h support for iio_device_claim_*()
      iio: light: vcnl4000: Use IIO cleanup helpers
      iio: health: max30102: Use IIO cleanup helpers
      iio: light: opt4060: Use IIO cleanup helpers

 drivers/iio/adc/ade9000.c                          |   2 +-
 .../common/cros_ec_sensors/cros_ec_sensors_core.c  |   5 +-
 drivers/iio/health/max30100.c                      |   2 +-
 drivers/iio/health/max30102.c                      |  33 ++---
 drivers/iio/industrialio-core.c                    |  86 ++---------
 drivers/iio/light/opt4060.c                        |  52 +++----
 drivers/iio/light/vcnl4000.c                       |  49 +++----
 include/linux/iio/iio.h                            | 162 +++++++++++++++++++--
 8 files changed, 210 insertions(+), 181 deletions(-)
---
base-commit: daea3a394a8b425a2dd206ab09eb37f0d1087d35
change-id: 20251130-lock-impr-6f22748c15e8

-- 
 ~ Kurt